A prior art switch assembly of this type comprises a case and a slider which are formed in separate bodies and coupled together by inserting the slider in a guide hole of the case. The coupled body is mounted on a wafer prepared separately. One example of this assembly is shown in FIGS. 12 through 16. FIG. 12 is a side elevation of the prior art switch assembly which generally comprises a wafer 3 having a pair of downward projecting terminals 1 and 2, a case 4 provided on the wafer 3, and a slide 6 received in a guide hole 5 of the case 4.
The terminal 1 is electrically connected to a contact 7 in the form of a coil spring, and the terminal 2 is electrically connected to a contact 8 in the form of a clip at the other side. One end of the slide 6 is snappingly pushed upward in FIG. 13 and contacts a contact portion 7a of the coil spring contact 7. The other end of the slide 6 passes through the guide hole of guide member 5a formed on the case 4 reciprocally up and down in FIG. 13. On the other hand, a mount portion 4a of the case 4 for engagement with the wafer 3 is provided at both ends thereof with engage recesses 4b-4b engageable with engage projections 3a-3a formed on both lengthwise end surfaces of the wafer so that the case 4 is inseparably held on the wafer 3 due to the resiliency of the case itself unless it is removed by intention.
On manufacturing the switch assembly, a base board 9 having terminals 1 and 2 is punched out from a metal plate in the form of a hoop and having a good conductivity. Thereafter, as shown in FIG. 15, a receptor plate 10 made of a metal conductor is provided on the terminal 1 to support the coil spring contact 7 for reliable contact therebetween, and the aforegoing clip-shaped contact 8 is provided on the terminal 2. The hoop material is transported according to a predetermined manufacturing process to make the box-shaped wafer 3 which includes the receptor plate 10 and contact 8 in central positions as shown in FIG. 16. The contact 7 is mounted on the receptor plate 10 with a coil portion 7c of the contact 7 contacting therewith. The slide 6 is inserted in the guide hole 5 of the case 4 upwardly in FIG. 16, and the case 4 receiving the slide 6 therein is applied to the wafer 3 downwardly, resiliently engaging the engage projections 3a-3a with the engage recesses 4b-4b. The coil spring contact 7 is supported by a contact stopper 4 d extending downward from an upper plate 4e of the case 4, and the contact end 7b is loosely received in a guide slit 4c. Reference numeral 4f (FIGS. 13 and 14) denotes a mount hole to fix the assembly to a panel or other support member.
In the switch assembly, when the contact end 7b of the contact 7 abuts the lower surface of a push portion 6a at the lower end of the slide 6 and pushes the slide 6 in the A direction in FIG. 13, the contact portion 7a moves by an amount equal to the movement amount of the slide 6 up to a stopper 3b at the bottom of the wafer 3. At that time, still referring to FIG. 13, the contact end 7b of the contact 7 located at a position substantially parallel to the push portion 6a of the slide 6 is contactingly sandwiched by a clip-shaped slidable portion 8a of the contact 8 which is electrically connected to the terminal 2, and the contact portion 7a slidably moves until it abuts the stopper 3b and closes the circuit. When compression is removed from the slide 6, the contact portion 7a is rotated in the B direction in FIG. 14 by the resiliency of the coil portion 7c of the contact 7, pushing the slide 6 in the C direction. When the contact portion 7a returns to its original position, pushing back the slide 6, the contact end 7b moves apart from the slidable portion 8a of the contact 8 and opens the circuit.
The switch assembly is usually mounted adjacent a movable member of a system and configured to activate the slide 6 in response to movement of the movable member, so as to detect the position of the movable member or establish an expected operation subsequent to movement of the movable member.
In such a use of the switch assembly, the slide 6 is mounted engageably with the movable member. Therefore, the assembly must be significantly small-scaled to never disturb movement or placement of other members of the system. This means that individual parts or members of the assembly are extremely small and make it difficult to couple or assemble them. Among these parts or members, the slide 6 particularly invites a trouble that it is apt to drop before the case 4 is brought in position of the wafer, because the slide 6 is inserted in the case 4 from the bottom, and the case 4 is coupled on the wafer, facing the bottom downward.